The invention relates to swimming pool heat pumps of the type used to heat the water in a swimming pool, and more particularly it relates to a multi-section evaporator, and a method of using the same.
1. Field of the Invention
The invention relates to the fields of heat pumps in general and swimming pool heaters in particular, especially the evaporator units employed in such heat pumps.
2. Description of Related Art
Swimming pool heat pumps are known in the prior art. Such heat pumps utilize ambient air to increase the amount of heat available to heat the pool water, spa water or hot tub water. They customarily do so by multiplying the energy put into the water heater from the electric power line several times, which makes the unit more cost effective to operate. Typically, this multiplication effect, called Coefficient of Performance (COP), will be 4 to 6, but only in ideal operating conditions.
Many known forms of swimming pool heat pumps are designed to operate most efficiently in warm humid weather, similar to the climate present in Florida and other southern coastal states, where there is a relatively narrow range between daily temperature highs and lows. Such heat pumps will not operate efficiently and may even be unreliable in desert climates, such as found in Arizona, where the temperature can range very widely, say from 30.degree. F. to 115.degree. F., and where the relative humidity remains in the low range from 15% to 30%. In such climates, the COP of known heat pumps can fall dramatically at the low temperature low humidity conditions, and at the high temperature conditions the heat pump may break or fail.
The key component of such heat pumps is the evaporator. Heat pump evaporators are very sensitive to the amount of moisture in the air which pass over them. Devices that are designed to operate in humid climates, like Florida, contain evaporators optimized for such humid conditions. A heat pump containing this form of evaporator will not be as efficient, and may not even operate, at the lower outdoor temperatures, and in low humidity conditions, like those found in Arizona. As a result, a heat pump containing such an evaporator might not even work to heat the swimming pool water in such conditions.